I just ran 'chmod -x /bin/chmod'. What did I do? How do I recover?

( or )

What to do if you cannot execute CHMOD?

This is a tricky question.. you have just removed execute permission on chmod.
Result of that is you cannot modify file permissions . Not even for chmod itself .
chmod remains usless on your system.

Here is the solution for the problem

sudo /lib/ld-linux.so.2 /bin/chmod 755 /bin/chmod

or

perl -e 'chmod(0755, "/bin/chmod")'

Solution : Backtrack 5 Live blank screen

I have downloaded backtrack 5 DVD and was trying to live boot from my Laptop.

Once i am in text mode and as root user.

I gave command startx

Just to turn command mode to GUI mode .

My system was showing a blank screen .. Searched online but did not find solutions

So I have tried my own troubleshooting methods and found that it was Graphics related issue.

Fix : Hope problem is because you are using a laptop with graphic card and BT is not able to
load specific drivers for your graphic card.
So go to BIOS either disable graphic card or

Change Graphic mode from Switching to discrete

for me it worked !! let me know if you still have problems will come up with other solutions...